Return bend fitting



p 1939- c. B. HARBISON 2,173,202

RETURN BEND FITTING Filed Oct. 17, 1938 2 Sheets-Sheet l Sept. 19:, 1939.

C. B. HARBISON RETURN BEND FITTING Filed Oct. 17, 1938 2 Sheets-Sheet 2 awe/Mm C/arence 5 flaw/50x7 Patented Sept. 19, 1939 UNITED STATES PATENT OFFICE RETURN BEND FITTING a corporation of Ohio Application October 17, 1938, Serial No. 235,307

3 Claims.

This invention relates to improvements in return bend fittings for oil refineries, and more particularly to such return bends in which the two yokes of said fittings are made in separate pieces to permit individual replacement of the tube conneeted to either yoke without disturbing the companion yoke or attached parts.

The primary object of the present invention is the provision, of simple and improved means for connecting together the separate yokes of a return bend of this class in a manner to prevent relative lateral twisting of the yokes or relative movements thereof axially of the connected tubes, and which at the same time permits easy and :rapid assembly and connecting of .the yokes in a tube bank.

Further objects and advantages of the invention will be apparent from the following detailed description and from the accompanying drawings, in which Figure 1 is an outer end View of a return bend embodying the invention with parts broken away and parts removed; Fig. 2 is a central longitudinal section thereof; Fig. 3 is a side elevation of one form of clamping means embodying the invention; Fig. 4 is a section on the line 44 in Fig. 3; Fig. 5 is a fragmentary view similar to Fig. 3 with the clamping means provided with one threaded stud; Fig. 6 is a View similar to Fig. 1 showing a slightly modified form of the clamping means with parts thereof broken away; Fig. 7 is a section on the line 'l'| in Fig. 6, and Fig. 8 is a side elevation of this modified form of clamping means.

In the embodiment of the invention illustrated in the drawings, I, l designate the two separate yokes of a return bend adapted to be assembled in side by side relation and each having an opening 2 therein in which the end of a refinery still tube (not shown) may be suitably secured in parallel relation to its companion tube.

A U-bend member 4 connects the outer ends of the openings 2 of a pair of yokes and is held in seated engagement with the yokes in any suitable manner as well understood in the art. The

manner of mounting and holding the U-bend member in engagement with the yokes forms no part of the present invention and need not be described.

Referring now to my improved clamping means for fastening a pair of yokes I together, and particularly to the form shown in Figs. 1 to 4, it will be noted that the adjacent or inner side of each yoke I is provided with a boss-like extension I0, 55 preferably of rectangular form in cross section.

The adjacent faces ll of these extensions are plain, or substantially so, and are disposed in spaced parallel relation when the yokes are properly assembled. At the inner and outer end edges of each extension ID are formed opposing grooves I 2 and I3, respectively. Each of these grooves is parallel to the adjacent margin of the respective face H and has its bottom surface inclined at an acute angle to said face so that each extension, in longitudinal section, is of dovetail form.

An insert l5 of substantially rectangular block form is removably disposed between the extensions IU of an assembled yoke pair and coacts with the opposing faces H thereof to hold the yokes in proper spaced relation to suit the desired spacing of the connected tubes. These inserts have flat abutting engagement with the extension faces II and are free to have sliding movements in any direction parallel to said faces except for the clamping feature hereinafter described.

The insert I 5, at its inner end, is provided with a cross-head I6 adapted to overlap the inclined walls of the grooves l2 of connected yokes and having undercut inclined portions I! for complemental wedging engagement with such walls. The insert l5, at its outer end, has one or more threaded studs l8 projecting therefrom in the major plane of the insert and through registering apertures in a clamping piece [9 which is similar in form to the cross-head I6. This clamping piece overhangs the inclined walls of grooves 13 of a yoke pair and has inclined portions 2|] in complemental wedging engagement with said walls.

Nuts 2| are threaded on the stems l8 and cooperate therewith to draw the head l6 and clamp piece IQ of the insert into clamping coaction with the engaged extensions. It is apparent that the clamping of the extensions ID in this manner is of a wedging nature tending to draw such extensions against the insert and to prevent relative movement of the yokes longitudinally of their openings.

In the present instance, the insert l5 has coaction with the extension faces I I only at its corners, being provided for such purpose with the corner bearing portions 22. Also, the wedging portions l1 and 20 of the head l6 and clamping piece [9 are short lengthwise of said parts and coact with the extensions ID at the end portions only of their respective edges. In Figs. 1-3, the insert is shown as having two threaded studs l8 and in Fig. 5 as having only one of such studs.

In the use of yoke clamping means of this character, it is important in practice to provide some means other than the opposed gripping or clamping action of the parts l6-l9 against the extensions IE} to prevent lateral relative twisting actions of the engaged yoke pair, and such means should be operative for this purpose whether the yoke parts are held firmly by the clamping means against relative longitudinal movements or are loose to permit such movements to a limited extent. An important feature of the present invention for this purpose is the provision of angularly projecting lugs on the ends of the clamping parts 16 and I9 to lap and engage the respective ends of the extensions Hl. Each lug 25 is of sufficient width to span the adjacent ends of the insert l5 and to lap the respective ends or corner portions of the extensions Iil at the sides thereof which are longitudinal to the yokes i.

It is apparent that the wedging portions l7 and 20 of the clamping part l6 and !9 engage the upper and lower edges of the extensions E9 to draw the extensions together and tend to prevent relative longitudinal movements of the engaged yokes, while the lugs 25 engage the respective corner portions of the side edges of said extensions to prevent any relative lateral twisting movement of the yokes. The lugs 25 have sliding coaction with the sides of the extensions 58 longitudinally of the yokes so that they will gitudinally recessed as shown at 36 to permit the stem clamping bolt 32 to extend therethrough. This stem is spaced from the side walls of the recesses 3| so that it does not in any way act to prevent relative lateral twisting movements of the yokes. The stem at its lower and upper ends is provided with a cross-head 33 and clamping piece 34 which are similar to the parts it and IQ of the form previously described and coact with the respective upper and lower inclined edge surfaces of the extensions in a similar manner thereto to draw the yoke together and prevent relative longitudinal movements thereof. The parts 33 and 34 are also provided at their ends with lugs 35 which coact with the sides of the ex tensions 30 in the same manner that the lugs 25 coact with the sides of the extensions ll] of said previous form.

So far as the engagement of the clamping means with the extensions of an associated yoke pair is concerned, the action is similar to that of my prior Patent No. 1,862,748, isued June 14, 1932, and the present improvement of such patent resides primarily in the making of the clamping elements in such form and the provision of the end lugs thereon as to enable the clamping elements to coact with the side edges of the adjacent side extensions of the yokes to prevent relative lateral twisting action of the yokes without interfering with the clamping action or with any permissible relative longitudinal movement thereof should such movement be desired.

I wish it understood that my invention is not limited to any particular construction, arrangement or form of the parts as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent, is:

1. A return bend fitting, including a pair of separable yokes having confronting faces, and means to connect the yokes together including an intermediate plate-like member having a movable part interposed between and engageable with the confronting faces of the yokes to hold same in spaced relation, said yokes and member having complementary wedging parts, means to clamp the movable part of the spacing member onto the latter whereby to cause the wedging parts to effect movement of the yokes against the spacing member thereof to tightly clamp all of the parts together, and means carried by the connecting means and engaged with the yokes whereby to prevent lateral twisting of the yokes relative to each other.

2. A return bend fitting in accordance with claim 1, wherein the spacing member and the movable part thereof have lugs, which, extend across the line of separation of the yokes, and which overlap each of the adjacent side faces of the yokes, to prevent lateral twisting of the yokes relative to each other.

3. A return bend fitting including a pair of separable yokes having confronting faces, an inner member, and an outer member, said yokes and members having complementary parts which wedgingly engage each other, means to draw the members together and thereby the yokes, and means at each of the ends of the members extending across the line of separation thereof and overlapping each of the adjacent side faces of the yokes to prevent lateral twisting of the yokes relative to each other.

CLARENCE B. HARBISON. 

